1. Technical Field
This invention relates in general to hinge mechanisms and in particular to a self-captivating, pinless hinge.
2. Background Art
In mechanical closure designs, there is a consistent need and preference to have doors or access panels hinge out of the way rather than be entirely removed from the underlying structure. This is usually accomplished by inserting a pin into a series of hinge curls extending from the door and the base it is mounted to. In the computer and electronic industry, another common method is to insert tabs into holes in mating parts. The tabs rotate in the holes to provide the hinge feature. Although these two hinging methods are widely used, they have disadvantages.
One problem with these types of hinges is their installation difficulty. For example, hinges that use the pin and curls design can be difficult to access due to the space required to properly insert the pin into the hinge curls. Larger hinges with long pins require even greater space for installation. Other problems with this design include pin retention and cost. During shipping or other high vibration environments, the pin can eventually work itself free of the hinge curls. The cost of the pin and hinge curls are relatively high due to tooling costs and the labor time involved in installing the pin.
Hinges that use the tab and hole design require the assembly of multiple parts at initial set up in order to support the hinged door or panel. In addition, this design occasionally requires the parts to be temporarily bent or deformed in order to insert the tabs into the holes of the mating parts. Thus, a hinge that is easy to install and retain in its underlying support structure while significantly reducing or eliminating installation cost and tooling is needed.
A hinge assembly has a hinge door that is pivotally mounted to a hinge base. The door has a flat body with a pair of square tabs extending laterally from one end. The hinge base has a flat frame with a rectangular aperture. A pair of parallel, rigid flanges extend from the aperture in the frame. Each flange has an entry hole that leads into a diagonal slot. The slots terminate in circular recesses.
The hinge door is installed in the hinge base to form the assembly by initially positioning the tabbed end of the door diagonally in the aperture. The tabs are then elevated slightly above the frame and rotated into alignment with the entry holes. The door is angled into alignment with the diagonal slots and lowered in that plane. This motion causes the tabs to move past the entry holes, through the slots, and into the circular recesses to form the hinge assembly. The recesses closely receive the tabs on the door to allow pivotal motion therebetween.